BACTERIA IN THE INDUSTRIES 



171 



colloidal transformation series, in which water, enzymes and bacteria play 

 the leading role. 



Bacterial Soil Inoculation— Bacterial Fertilizers.— By means of thor- 

 ough soil cultivation and the systematic use of fertilizers we simply encour- 



FiG. so.— Longitudinal section through red clover rootlet, showing tubercle forma- 

 tion due to the root nodule microbe, Rhizobium mutaUle. The tubercle is only partiaUy 

 developed, a. root hairs. These do not develop on the nodule. 6, the normal root 

 parenchyma, c, vascular tissue, d, infected area, also showing the infectmg strands 

 (.InfectionsfSden). The cells are filled with bacteria, e. apical areas, the growmg areas 

 of the tubercle. 



